/*
 * fontconfig/src/fccompat.c
 *
 * Copyright © 2012 Red Hat, Inc.
 *
 * Author(s):
 *  Akira TAGOH
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of the author(s) not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  The authors make no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "fcint.h"

#include <errno.h>
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#ifdef O_CLOEXEC
#define FC_O_CLOEXEC O_CLOEXEC
#else
#define FC_O_CLOEXEC 0
#endif
#ifdef O_LARGEFILE
#define FC_O_LARGEFILE O_LARGEFILE
#else
#define FC_O_LARGEFILE 0
#endif
#ifdef O_BINARY
#define FC_O_BINARY O_BINARY
#else
#define FC_O_BINARY 0
#endif
#ifdef O_TEMPORARY
#define FC_O_TEMPORARY O_TEMPORARY
#else
#define FC_O_TEMPORARY 0
#endif
#ifdef O_NOINHERIT
#define FC_O_NOINHERIT O_NOINHERIT
#else
#define FC_O_NOINHERIT 0
#endif

#if !defined (HAVE_MKOSTEMP) && !defined(HAVE_MKSTEMP) && !defined(HAVE__MKTEMP_S)
static int
mkstemp (char *template)
{
    static const char s[] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    int fd, i;
    size_t l;

    if (template == NULL)
    {
	errno = EINVAL;
	return -1;
    }
    l = strlen (template);
    if (l < 6 || strcmp (&template[l - 6], "XXXXXX") != 0)
    {
	errno = EINVAL;
	return -1;
    }
    do
    {
	errno = 0;
	for (i = l - 6; i < l; i++)
	{
	    int r = FcRandom ();
	    template[i] = s[r % 62];
	}
	fd = FcOpen (template, FC_O_BINARY | O_CREAT | O_EXCL | FC_O_TEMPORARY | FC_O_NOINHERIT | O_RDWR, 0600);
    } while (fd < 0 && errno == EEXIST);
    if (fd >= 0)
	errno = 0;

    return fd;
}
#define HAVE_MKSTEMP 1
#endif

int
FcOpen(const char *pathname, int flags, ...)
{
    int fd = -1;

    if (flags & O_CREAT)
    {
	va_list ap;
	mode_t mode;

	va_start(ap, flags);
	mode = (mode_t) va_arg(ap, int);
	va_end(ap);

	fd = open(pathname, flags | FC_O_CLOEXEC | FC_O_LARGEFILE, mode);
    }
    else
    {
	fd = open(pathname, flags | FC_O_CLOEXEC | FC_O_LARGEFILE);
    }

    return fd;
}

int
FcMakeTempfile (char *template)
{
    int fd = -1;

#if HAVE_MKOSTEMP
    fd = mkostemp (template, FC_O_CLOEXEC);
#elif HAVE_MKSTEMP
    fd = mkstemp (template);
#  ifdef F_DUPFD_CLOEXEC
    if (fd != -1)
    {
	int newfd = fcntl(fd, F_DUPFD_CLOEXEC, STDIN_FILENO);

	close(fd);
	fd = newfd;
    }
#  elif defined(FD_CLOEXEC)
    if (fd != -1)
    {
	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
    }
#  endif
#elif HAVE__MKTEMP_S
   if (_mktemp_s(template, strlen(template) + 1) != 0)
       return -1;
   fd = FcOpen(template, O_RDWR | O_EXCL | O_CREAT, 0600);
#endif

    return fd;
}

int32_t
FcRandom(void)
{
    int32_t result;

#if HAVE_RANDOM_R
    static struct random_data fcrandbuf;
    static char statebuf[256];
    static FcBool initialized = FcFalse;

    if (initialized != FcTrue)
    {
	initstate_r(time(NULL), statebuf, 256, &fcrandbuf);
	initialized = FcTrue;
    }

    random_r(&fcrandbuf, &result);
#elif HAVE_RANDOM
    static char statebuf[256];
    char *state;
    static FcBool initialized = FcFalse;

    if (initialized != FcTrue)
    {
	state = initstate(time(NULL), statebuf, 256);
	initialized = FcTrue;
    }
    else
	state = setstate(statebuf);

    result = random();

    setstate(state);
#elif HAVE_LRAND48
    result = lrand48();
#elif HAVE_RAND_R
    static unsigned int seed = time(NULL);

    result = rand_r(&seed);
#elif HAVE_RAND
    static FcBool initialized = FcFalse;

    if (initialized != FcTrue)
    {
	srand(time(NULL));
	initialized = FcTrue;
    }
    result = rand();
#else
# error no random number generator function available.
#endif

    return result;
}